On outindependent subgraphs of strongly regular graphs
An outindependent subgraph of a graph G, with respect to an independent vertex subset C¿¿V, is the subgraph GC induced by the vertices in V\¿C. We study the case when G is strongly regular, where the results of de Caen [1998, The spectra of complementary subgraphs in a strongly regular graph. Europe...
| Autores: | , |
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| Formato: | artículo |
| Fecha de publicación: | 2006 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/126902 |
| Acesso em linha: | https://hdl.handle.net/2117/126902 |
| Access Level: | acceso abierto |
| Palavra-chave: | Combinatorial analysis Graph theory Strongly regular graph Independent set Spectrum Combinacions (Matemàtica) Grafs, Teoria de Classificació AMS::05 Combinatorics::05E Algebraic combinatorics Classificació AMS::05 Combinatorics::05C Graph theory Àrees temàtiques de la UPC::Matemàtiques i estadística::Matemàtica discreta::Combinatòria Àrees temàtiques de la UPC::Matemàtiques i estadística::Matemàtica discreta::Teoria de grafs |
| Resumo: | An outindependent subgraph of a graph G, with respect to an independent vertex subset C¿¿V, is the subgraph GC induced by the vertices in V\¿C. We study the case when G is strongly regular, where the results of de Caen [1998, The spectra of complementary subgraphs in a strongly regular graph. European Journal of Combinatorics, 19 (5), 559–565.], allow us to derive the whole spectrum of GC . Moreover, when C attains the Hoffman–Lovász bound for the independence number, GC is a regular graph (in fact, distance-regular if G is a Moore graph). This article is mainly devoted to study the non-regular case. As a main result, we characterize the structure of GC when C is the neighborhood of either one vertex or one edge. |
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